From the problem, we have the expression :
[tex]7^{-10}[/tex]Note that negative exponents are written in the denominator for them to be positive.
[tex]a^{-n}=\frac{1}{a^n}[/tex]So that will be :
[tex]7^{-10}\Rightarrow\frac{1}{7^{10}}[/tex]ANSWER :
[tex]\frac{1}{7^{10}}[/tex]